Engineering Sialylation into Insect Cells

Shawn Lawrence, Lee Pitts, Tim Coleman, Yuan C. Lee, Willie Vann, Michael Betenbaugh
Johns Hopkins University
3400 N. Charles St.
Baltimore, MD  21218
shawn.lawrence@jhu.edu
(410)516-5336

The carbohydrate content of a glycoprotein, especially sialic acid, can effect its solubility, biological activity, and circulatory half-life.  Glycoproteins generated by insect cells with the baculovirus expression vector, however, contain little if any bound sialic acid.  In order to provide sialylation, methods must be implemented to express the relevant enzymes.  Genomic databases can be used to identify the critical sialylation genes.  These genes are then inserted into baculovirus vectors for expression in insect cells.  Enzyme activity is measured to determine the effect of insertion of the foreign gene and its role in the sialylation of glycoproteins.